Improved Collision Cone Control Barrier Functions for Dynamic Obstacle Avoidance of UAVs

This paper proposes an improved collision cone control barrier function (IC3BF) for unmanned aerial vehicles (UAVs) to enable collision avoidance without violating control limits under dynamic-obstacle scenarios. While current forms of collision cone control barrier function (C3BF) have been successful in collision avoidance with static and dynamic obstacles, UAV control under actuator limits remains challenging. Conflicts of safety constraints and control limits lead to unsolved optimization problems, which are effectively resolved by the proposed method. The core innovation of IC3BF is the introduction of a time-varying relaxation radius, which partially relaxes the original safety constraints of C3BF. The relaxation is formulated as a control barrier function (CBF) with auxiliary dynamics stabilized by a control Lyapunov function (CLF). The proposed method shows significant advantages, reducing the conservatism of C3BF and providing smoother trajectories with lower control input.